What type of wall construction used in your granny flat?

[kennyboi]

I am undecided which wall construction type (timber frame or full brick) to use for my granny flat, so I like to hear what you used and why.

My concern with timber frame is it will get easily hot inside on a hot summer day and can be hard to rent out. If there is tenant, they may move out more frequently. But the pro to timber frame is 12k cheaper to build and an extra room due to thinner wall giving extra 5 sqm.

Thanks

 

[neK]

There is plenty of insulation... heat is not an issue.
I had a tenant in mine for 3 years.
There was an air con, they said the temp was pretty good all year around they turned on the air con on average 3 times per year.

Also when you say full brick, I assume you mean brick veneer. As double brick would use up more than just 5sqm.

 

[kennyboi]

There is plenty of insulation... heat is not an issue.
I had a tenant in mine for 3 years.
There was an air con, they said the temp was pretty good all year around they turned on the air con on average 3 times per year.

Also when you say full brick, I assume you mean brick veneer. As double brick would use up more than just 5sqm.

Mind if I ask if you use foam or wool wall insulation? Is it 450 or 600 eaves?

I mean double brick (270 / 110). It's only marginally more than brick veneer (250 / 100) in wall area.

 

[Brian84]

I am a builder by trade and I recommend if its for an investment you don't need to spend a fortune on a granny flat. The less you spend the more you make so what I would do is either one of the following options in order from least expensive to most expensive.
1/ timber frame with external wall wool insulation with blue board or hebel on the external walls with render applied over the blue board or Hebel.
2/ timber frame with wool insulation with brick veneer which you see around 95% of new homes.
3/270mm double brick wall with timber frame internal walls or double brick internal walls. Personally I think this option would be a waste of money for a granny flat.

Hope this helps.

 

[kennyboi]

I am a builder by trade and I recommend if its for an investment you don't need to spend a fortune on a granny flat. The less you spend the more you make so what I would do is either one of the following options in order from least expensive to most expensive.
1/ timber frame with external wall wool insulation with blue board or hebel on the external walls with render applied over the blue board or Hebel.
2/ timber frame with wool insulation with brick veneer which you see around 95% of new homes.
3/270mm double brick wall with timber frame internal walls or double brick internal walls. Personally I think this option would be a waste of money for a granny flat.

Hope this helps.

Hi, I was thinking of option 1, but I am concern it may become unbearably hot during summer in Sydney's 40+ degree weather.

Does wool insulation become less effective over time as it absorbs moisture and sag? What's the best wall insulation for timber frame these days?

 

[Brian84]

I live in Sydney and my neighbours have a double storey blue board house and they don't have a problem with temperature in summer or winter. In regards to insulation you can use bradfords, earth wool, pink batts. They are all good. Use the ones with rating of 1.5-2. If you end up doing blueboard make sure the carpenters put sparking on the outside of the wall before installing the blueboard the the frame.

Another tip is to make sure the renderers use acrylic render as it is a bit flexible once it is dried and will allow for movement in the frame and won't crack as apose to cement render where it will crack.

Acrylic render can have your choice of paint colour mixed in at no extra cost so it won't need painting.

 

[kennyboi]

I live in Sydney and my neighbours have a double storey blue board house and they don't have a problem with temperature in summer or winter. In regards to insulation you can use bradfords, earth wool, pink batts. They are all good. Use the ones with rating of 1.5-2. If you end up doing blueboard make sure the carpenters put sparking on the outside of the wall before installing the blueboard the the frame.

Another tip is to make sure the renderers use acrylic render as it is a bit flexible once it is dried and will allow for movement in the frame and won't crack as apose to cement render where it will crack.

Acrylic render can have your choice of paint colour mixed in at no extra cost so it won't need painting.

What's life expectancy like on the acrylic render and are they zero maintenance once installed?

 

[Brian84]

If done properly it should last atleast 25 yrs. no maintenance required unless a crack arises which is an easy fix. Cracks happen in every construction product, concrete cracks, brickwork cracks, paint cracks, gyprock cracks etc. personally I would go with the blueboard. Quickest and cheapest

 

[kennyboi]

If done properly it should last atleast 25 yrs. no maintenance required unless a crack arises which is an easy fix. Cracks happen in every construction product, concrete cracks, brickwork cracks, paint cracks, gyprock cracks etc. personally I would go with the blueboard. Quickest and cheapest

What do you think of Duratuff Vinyl cladding? It seems to be the cheapest option offered by granny flat builders.

 

[neK]

Used it twice.... no complaints.

Would i use it again? No. It looks cheap.

Used on two dwellings James Hardie Primeline Heritage (http://www.jameshardie.com.au/products/external-cladding/primeline-weatherboard/) and Scyon Stria (http://www.jameshardie.com.au/products/external-cladding/scyon-stria-cladding/) I liked the look of the finish product on both.

For a newer build, i think the Scyon Stria worked quite nicely.... but only where there are long vertical windows at the front.... otherwise it looks like a toilet block.

 

[robboat]

I used timber frames with Weathertex cladding and Bradford insulation on our GF build.
The batts fit neatly straight into the frames...
Works better than the main house and the air con only get used a few times a year.
No tenant complaints in 40c+ weather in Sydney last few summers.

Build the GF for the lowest cost you can...easy rent if layout is good, has parking, access is private and it is presented properly.

Tip is to make sure the insulation is installed properly with less than 5% air gaps overall....takes time.

 

[Brian84]

I agree with nek. Vinyl cladding looks cheap and is out dated. I personally wouldn't use it because I don't like it, that's just my 2 cents

 

[sanj]

If you're considering brick veneer and are concerned about how hot it gets pls for the love of god do reverse brick veneer

Timber frame can work well, you just need to design and specify it correctly. Uninsulated double brick homes can also be bloody warm

 

[Brian84]

You are only building in Australia so a brick veneer or timber frame and clad home will be sufficient.

 

[kennyboi]

The options you guys mentioned, are they maintenance-free products once installed? Any idea how much more $ compare to vinyl?

Which timber is better for framing, pine or oregon?

Should I go for H2 termite/pest treated timber? Does treatment shortens lifespan compare to untreated?

 

[paul81]

I agree with Brian, build as cheap as you can. Both my granny flats are brick veneer but only because i could get them built as cheap as blue board and personally i think brick looks better.

 

[Brian84]

H2 is probably the best because its treated for termites where as oregan and normal pine isn't. If you can afford it do brick veneer but if you are on a budget just do blueboard

 

[kennyboi]

I agree with Brian, build as cheap as you can. Both my granny flats are brick veneer but only because i could get them built as cheap as blue board and personally i think brick looks better.

I agree too, but having a second layer of wall loose about 5sqm of usable floor space.

 

[kennyboi]

H2 is probably the best because its treated for termites where as oregan and normal pine isn't. If you can afford it do brick veneer but if you are on a budget just do blueboard

Does blueboard with acrylic render you mentioned require repaint every few years, or absolutely no maintenance? Is it worth paying extra for it compare to Vinyl?

Is there anything wrong with vinyl other than looking cheap? My front house is in permalume cladding, it seems Duratuff vinyl cladding look similar to permalume for match.

Also, does H2 treatment shorten life of pine timber compare to untreated pine? Any idea roughly how long does treatment last?

Thanks

 

[Brian84]

Does blueboard with acrylic render you mentioned require repaint every few years, or absolutely no maintenance? Is it worth paying extra for it compare to Vinyl?

Is there anything wrong with vinyl other than looking cheap? My front house is in permalume cladding, it seems Duratuff vinyl cladding look similar to permalume for match.

Also, does H2 treatment shorten life of pine timber compare to untreated pine? Any idea roughly how long does treatment last?

Kennyboi,

It might require painting every 10 years atleast possibly but that will allow you to keep up to date with colour trends unless you do a neutral colour.

Permalume is pretty much vinyl cladding.

H2 is guaranteed for 25 years